Adds a child group to
parentGroup, or the repeater model if
null, using the drop event
e.
If
indexToInsert is provided the group is inserted at that position, otherwise it is added to the end.
The drop event. Can contain a desktop file drag/drop operation, native structure node, metric set node, or suitable data element node.The parent repeater group to insert into, or null if inserting a top-level group.(optional) An index in the groups array at which to insert the group. If not specified, the group will be added to the end.A promise object that is resolved when the call is complete.
If successful, the new dundas.controls.RepeaterGroup is returned if the event contains a suitable data source, or null otherwise.